Fiber-Hungry Bacteria Could Form Natural
"Bond" With Wood Industry

The tiny, gut-dwelling bacteria that help cows and other
herbivores break down the tough fiber in their diets could someday find their
way into various wood products and furniture.

An Agricultural Research
Service scientist has found that these microbes' ability to secrete a
sticky outer coating provides the ideal basis for a biologically based wood
"glue." Brought about through fermentation, this adhesive residue is strong
enough to create wood products like plywood and particleboard.

ARS microbiologist Paul Weimer and
U.S. Forest Service collaborators have
discovered a way to combine strains of Ruminococcus bacteria and scrap
plant material--crop residue, wood chips and even recycled newspapers--to form
a sticky fermentation residue that boasts powerful adhesive properties.

The all-natural residue could replace a portion of the
petroleum-based, phenol-formaldehyde (PF) resin currently used to bond multiple
layers of wood together. The researchers' invention could lead to a safer and
more environmentally friendly adhesive.

Weimer, who works at the ARS
U.S. Dairy Forage Research Center
in Madison, Wis., studies bacteria that reside in dairy cows' digestive tracts.
He stumbled upon the idea for a wood adhesive when observing how tightly
certain cellulose-digesting bacteria like Ruminococcus and
Clostridium bind to plant material while metabolizing.

These bacteria have an outer glycocalyx, or slime layer, that
allows them to cling to a surface, similar to how cavity-causing bacteria
adhere to teeth.

Weimer teamed up with Linda Lorenz, Charles Frihart and
now-retired Anthony Conner of the Forest Service's
Forest Products Laboratory in Madison,
Wis., for their expertise on conventional wood adhesives.

The bacterially based residues can replace up to 45 percent of
the amount of traditional adhesive, like PF resin, used in many wood
products--and even withstand moisture. Generated at minimal cost as a
co-product of fuel ethanol, the residues could also bring an economic boost to
the development of processes that convert plant materials into fuels.

Weimer and his colleagues have filed for a patent on their
research, so the technology is now available for licensing.